The quantum algorithm that would break certain kinds of public key cryptography schemes (not even the core part of Bitcoin blockchains, which are not vulnerable to quantum computers) will take days to weeks to break a single key [0]. This is another reason why we will have plenty of warning before quantum computing causes any major disruptions to daily life.
What I would start worrying about is the security of things like messages sent via end-to-end encrypted services like WhatsApp and Signal. Intercepted messages can be saved now and decrypted any time in the future, so it's better to switch to more robust cryptography sooner rather than later. Signal has taken steps in this direction recently: https://arstechnica.com/security/2025/10/why-signals-post-qu....